With the continuing increase of telephone traffic, telephone companies are attempting to make direct international or intercontinental dialing available to the users of pay telephones which at present are rather ill-suited for this type of service, being able to handle only coins up to a certain monetary value (usually 25 cents in the United States). Thus, a user would have to provide himself with a large number of tokens or coins of equivalent denomination unless pay stations were designed to handle denominations of higher value in the form of, say, paper money and/or prepayment credits on subscription cards. With these higher-valued payment items, however, there arises the problem of properly settling the incurred dept from the deposited funds without overcharging a caller who, usually, has no advance knowledge of the exact cost of the call and must therefore make available an excess amount to prevent premature cutoff. If the system were to accept, for example, one-dollar items in the form of coins, bills or tokens, and if the user deposits two such items for a call actually costing only $1.05, he would lose the excess payment of 95 cents; lower-valued coins, on the other hand, would be rapidly consumed on connections over larger distances and could not be fed in fast enough to keep up with the demand without unduly distracting the attention of the caller from the conversation in which he is engaged.